Cotter key



June 6, 1950 J. A. MacLEAN, JR., Erm. 2,510,897

COTTER KEY Filed Jan. 24, 1945 Patented June 6, 1950 UNITED STATES PATENT OFFICE COTTER KEY Application January 24, 1945, Serial No. 574,339

2 Claims.

Our invention relates to cotter keys and has for its object the provision of a Cotter key that is of simple sturdy construction and economical to manufacture and easy to install, which, after being properly placed in an appropriate Cotterreceiving hole of a bolt or pin or other part with which it cooperates, will have a multiplicity of surfaces of substantial area forcibly engaging and held against the wall of the hole, to the end that rattling of the Cotter key in the hole, and consequent Wearing of the Cotter key and the wall of the hole, will be eliminated.

Features of the Cotter key of the present invention are:

(a) Fulcra in the form of opposed contiguous protuberances, carried by the Cotter key legs intermediate their ends, on which the legs move as levers to establish the desired relationship between the legs and the wall of an appropriate Cotter-receiving hole when the Cotter key is properly placed in such hole;

(b) Initially spaced apart opposed protuberances, Carried by the legs intermediate the fulcra and the head-loop, which provide a secondary area of Contact between the legs after the latter have functioned as levers for the purpose aforestated;

(c) Leg portions that converge from the fulcra toward the free ends of the legs;

(d) Leg portions that diverge from the fulcra toward the initially spaced apart opposed protuberances; and

(e) In one of the two illustrated embodiments of our invention, leg portions that diverge from said initially spaced apart opposed protuberances toward the head-loop to adapt the Cotter key for reception by and appropriate cooperation with over sized Cotter-receiving holes as well as those of the particular size the Cotter key is primarily intended to fit.

The aforementioned and other features, objects and advantages of our invention will appear from the following detailed description wherein reference is made to the accompanying drawings:

In the accompanying sheet of drawings:

Figure l is an edge View, Fig. 2 is a side View, and Fig. 3 is an end view of one form of our improved cotter key as it appears before being placed in the Cotter-receiving hole of a bolt, pin or other part with which it is to cooperate;

Fig. 4 is a sectional View illustrating the afore-v mentioned Cotter key as it appears after being driven home into an appropriate Cotter-receiving Fig. 9 is a sectional view, generally similar to Fig. 8, illustrating a Cotter key of the same type as it appears after being appropriately installed in a Cotter-receiving hole that is somewhat oversize because of wear or some other reason.

Similar characters of reference refer to similar parts throughout the several views.

Referring first to Figs. l, 2 and 3, it will be observed that the Cotter key there depicted Coni sists of a piece of half-round metal wire that has been return bent to define the head-loop I and provide the legs 2 and 3. The flat faces of the legs are presented to each other and leg 3 preferably is somewhat shorter than leg 2. The halfround wire usually will be of one of the steels Y heretofore found suitable for Cotter key service.

In the formation of the Cotter key, the semicylindrical faces of its legs are dented, as indicated at 4 4, to form on the flat faces of the legs transversely extending beads or protuberances 5 5. These beads or protuberances 5 5 are intended initially to have line Contact with each other, as illustrated, and preferably curve away from their line of Contact toward the ends of the legs.

The semi-cylindrical faces of the legs 2 land 3 also are dented adjacent the head-loop, as indicated at 6 6, to form on the flat or inner faces of the legs transversely extending beads or protuberances 'I These beads or protuberances 1 1 are intended initially to lie in opposed spaced relation to each other as shown.

Except for the indentation 4 4 and 6 6 and the beads or protuberances 5 5 and 1 1, the legs 2 and 3 are substantially straight with their p01'- tions 2a and 3a converging away from the beads or protuberances 5 5, and with their portions 2b and 3b diverging away from such beads or protuberances15-5. The free end of leg 3 preferably lies immediately adjacent to the flat face of leg 2.

In Fig. 4 we have depicted at 18 a bolt, pin, or other part provided with a hole in the nature of a bore 9 for the reception of the Cotter key. The distance between the points A and B. on the por- 3 tions 2a and 3a of the legs, is preferably substantially equal to or slightly less than the diameter of the bore 9; whereas, the distance between the points C and D, on the portions 2b and 3b of the legs, is preferably definitely greater than the diameter of the bore 9.

After the free ends of legs 2 and 3 have been inserted in bore 9, the cotter keyV freely may be moved into such bore until the portions 2b and 3b of the legs have started to enter the same. Driving of the cotter key further into bore 9 causes movement of the legs 2 and 3 as levers on fulcra constituted by the contacting beads or protuberances 5 5, the portions 2b.and 3b.v of the legs being squeezed together,- .with consequent constriction of head-loop l, to locate their semi-- cylindrical faces in snug forcible contact with the wall of bore 9, and to bring theY beads or protuberances 1 1 together, and the portionsv 2a` and 3a of the legs separating to place their semicylindrical faces also in snug forcible contact withV See Fig. 4. When the-cotter tions assumed by the free ends of the legs before they havebeen thus conventionally spread apart.

The snug forcible contacts between the wall of bore 9 and the semi-cylindrical faces of the leg portions 2a, 3a,-2b, and 3b will be maintained indefinitely despite that the bolt, pin or other part B be subjected to excessive and/or continuous vibration. The beads'or protuberances 1 1, contacting as depicted in Fig. ,4, insure that blows sustained: by the head-loop I, whether received when` the cotter key is driven home into the hole l 9 or received later, will not divert theV leg portions 2b and 3bl of the cotter Akey Yfrom their forcible snug engagement with the Wall of the hole-9.

Inmanufacturing the cotter-key just described, thebeads or protuberances 5 5 and 1 1 preferably are flrstproduced on a suitable length of wire. which is then return bent and otherwise conformed to providel the head-loop l, to place the .beads or protuberances 5 5 in opposed immediate juxtaposition, and to place the beads or protuberances 1 1 in opposed suitably spaced apart relationship.

The cotter key illustrated in Figs. 5 to 9 comprises all of the elementsof the cotter key depicted in the preceding figures, and such elements have been designated in Figs. 5 to 9 by the same reference characters that have been applied to them in Figs. 1 to 4.

In addition to the elements that it has in common with the cotter key of Figsgl to 4 inclusive, the cotter key of Figs. 5 to 9 inclusive is characterized by leg portions 2cvand 3c which diverge away from the beads or protuberances 1 1, the distance between the points C and D on these leg portions 2c-and 3c being substantially greater Bore 9 may be v cotter keyunder discussion is primarily intended tot, and Fig. 8 showsI thatsaid-cotterfkey co-V operates with such bore 9 insubstantially the same manner that the cotter key of Figs. 1 to 4 cooperates with its corresponding cotter-receiving bore.

Attention is now directed to Fig. 9 which illustrates a part 8a having a cotter-receiving bore 9a which, due to wear or for some other reason, is of over-size diameter. The cotter key of Figs. 5, 6 `and '1 may be moved freely into the oversized cotter-receiving bore 9a until the leg portions 2c and 3c are about to enter such bore. Thereupon, when the cotter key is further driven in said bore to the extent indicated in Fig. 9, the legs 2 and 3 move as levers on fulcra represented by the Vbeads or protuberances 1 1, the portions 2c and 3c of the legs being squeezed together, with consequent constriction of the head-loop l. to locate ltheir semi-cylindrical faces in snug forcible contact with the wall of bore 9a, and the portions Zband 3b of the legs moving away from each other, with consequent separation of the beads or-protuberances-S, to place their'semicylindrical faces also in snug forcible contact With f the Y'wall of bore 9a; When the cotter key is formed of relatively soft metal stock, as usuallyl will be the case, the driving home of the cotter key will cause the opposed surfaces of the beads or protuberances 1 1 to flatten somewhat into forcible snugv face-to-face contact. the free ends of the cotter key legs conventionally may be spread apart, if desired.

The snug forcible contacts between the wall of bore 9a and the semi-cylindrical faces of the leg portions 2b, 3b, 2c and 3c willvbe maintained indefinitely despite that the bolt, pin or other partl 8a,rbe subjected to excessive and/or continuous vibration.

The cotter key of Figs. 5 to 1 inclusive is manufactured in substantially the same vmanner as is Y the cotter key of Figs; 1 to 3 inclusive.

Havingthus illustrated and described our linvention, what we claim as new and desire to secure byLetters Patent of the United States is:

1. A cotter key'adapted snugly to t into `a hole of appropriate size and having a pair of legs with substantially semi-circular sectional shape that are connected at corresponding ends with the flat l surfaces of their semi-circular section in opposition and notl connectedat their other ends, the

connected ends of the legs lbeing spaced apart and.

the other ends of rthe legs lying comparatively close together, a pair of opposed protuberances of substantial width on the legs at positions intermediate the ends of the legs and aligned for forcible-.engagement with one another so as together to serve as afulcrum on which the legs move relative to one another as levers when the cotter key is forced into a cotter-receiving hole of said ape. propriate size, substantial portions of said legs onopposite sides of said protuberances being substantially straight and practically in longitudinal alignment, and a second pairof opposed and normally spaced apartprotuberances on the legs,

lying intermediate the rst-named protuberances and theconnected ends of the legs and aligned to engageA each other'when the legs have moved as levers relative to the rst mentioned protuberances during the placement of the cotter key in a cotter-receiving hole of appropriate size.

2. A cotter key having a pair of legs that are connected .at` corresponding ends and` not connected at theirl other ends, the connected ends of the legsybeing spaced apart and the other-ends of a:

the legs lying comparatively close togethergtransverseV beads of substantial width'on opposed surfaces of the legsintermediate the ends of the legs;

Here again aardse? 5 said beads being normally engaged and aligned forcily to press against each other and to serve together as a fulcrum on which the legs move relative to one another as levers when the cotter key is properly forced into an appropriate cotterreceiving hole, and a second pair of transverse beads on opposed surfaces of the legs and disposed between the rst named beads and the connected ends of the legs, said legs having portions on opposite sides of said beads which are substantially straight and diverge outwardly toward the connected ends thereof, and said last-named beads being normally spaced apart and being aligned to engage each other when the legs have moved as levers on the mst-named beads serving 15 2,266,689 l as a fulcrum.

JOHN A. MACLEAN, JR. BENJAMIN FRANKLIN MONEY.

6 REFERENCES CITED UNITED STATES PATENTS Number Name Date 795,242 Wiss July 18, 1905 996,756 Germonprez July 4, 1911 1,233,195 Greech July 10, 1917 1,244,076 Pster Oct. 23, 1917 1,336,498 Aylor et al Apr. 13, 1920 1,425,367 Chase Aug. 8, 1922 1,605,433 Gibson Nov` 2, 1926 2,172,852 Reynolds Sept. 12, 1939 Lemison Dec. 16, 1941 

